TNF and irritable bowel syndrome: In a recent paper, Kaiko et al. identified a novel protein—plasminogen activator inhibitor 1 [PAI-1]—showing an important role in controlling key inflammatory modulators during mucosal damage in colitis.11 They also highlighted that the mucosal SerpinE1 gene [the gene encoding PAI-1] expression is elevated in active, more severe IBD patients who do not respond to anti-tumour necrosis factor [TNF] therapy.